Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a wireless mobile device. Wireless communication system standards and protocols can include the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) standard; the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which is commonly known to industry groups as WiMAX (Worldwide Interoperability for Microwave Access); and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi. In 3GPP LTE systems the radio access network (RAN) known as Evolved Universal Terrestrial Radio Access Network (E-UTRAN) includes the base station (also commonly denoted as E-UTRAN NodeB, eNodeB, or eNB), which communicate with a wireless communication device, known as user equipment (UE).
Proximity-based discovery and device-to-device (D2D) communication between devices (such as UEs) have gained strong interest because they provide the network operator the possibility to offer new types of applications and services for commercial, social, and public safety use. Furthermore, proximity-based discovery and D2D communication provide the network operator the possibility to temporarily offload user traffic exchanged between two UEs in proximity of each other from the network infrastructure to a D2D direct communication path.